There's an inherent bias towards treating government statements as fact (whether that's police, government officials or military spokesmen). When the other side is a 'terrorist organisation' or a 'community leader', they're automatically treated as biased and suspicious. It's a pattern you see with Israel, police shootings, etc.

Obviously when the country in question isn't aligned with the West (Russia, China, etc), the qualifiers and doubt comes creeping back in, and journalists will include examples of past lies to underscore the point, which you'll never see in a story about the NYPD or Matthew Miller.